Tool system that can be coupled to a lathe drive shaft

ABSTRACT

The invention relates to a tool system that can be coupled to the drive shaft of a lathe. Said system comprises a tool holding fixture which can be connected to the lathe, and a took which is stored in a polygonal recess in the tool holding fixture so as to be torsion-proof yet removable. This tool has a tool shank and at least one functional section extending coaxially therefrom. The tool rests axially on a centering area in the polygonal recess, and rests radially on several identical locking elements. These are arranged in radial cavities in the tool holding fixture, at equal angular distances and at an axial distance from the centering area. This enables centering of the tool in the tool holding fixture.

The invention relates to tool system that can be coupled to the driveshaft of a rotary tool, such as a hand drill or a screw drill.

Such a tool system is known from JP-A-4365563. Therein is at handessentially a so-called “bit holder”. The actual tool of this systemsare bits of varying sizes, whereby each individual tool at eachfront-face side has a bit section as functional section. Through thisthe tool is coupled to the drive machine that respectively one of thetwo bit points is clamped into a corresponding receiving device. Thishas the drawback that the bit itself is utilized for centering of thetool whereby the coupling in conformity with the size of the bit more orless is force-locking. This has the drawback that the functionalsections during use relatively quickly wear in conformity with thequality of the coupling. Additionally, in the device of JP-A-4365563there is contemplated an interlocking which, however, is acting onlyone-sided and, therefore, adds only in unsatisfactory manner to thecentering of the tool. This also increases wear of the respectivelyclamped functional section.

From EP-O 685 300 A1 is already known a tool system which can be coupledto a hand drill or a screw drill, which comprises a tool holding fixtureand a combination tool.

The combination tool has a shaft with hexagonal profile and twofunctional sections which extend coaxially therefrom and at oppositesides thereof. In use according to purpose the combination tool isreceived in a hexagonal recess of a sleeve-like adapter which is inconformity with the hexagonal profile of the tool shaft, which can beconnected to the drive shaft of the rotary tool and by means of a detentdevice can be axially fixed. The adapter is connectable with the driveshaft of a rotary tool. As detent device serves a detent ball receivedin a radial recess which transgresses the cylinder mantle of theadapter. In a locking position the detent ball projects with a calotteinto the recess of the adapter and extends into a surrounding radialgroove in the shaft of a tool which is received in the adapter. Thedetent ball is held in the locking position by a calotte which isaxially movable on the adapter forward into the recess of the adapterforward and extends into a surrounding radial groove in the shaft of atool received in the adapter. The detent ball is held in the lockingposition by a locking sleeve which is axially movably received on theadapter, which due to the axial displacement can be moved into aposition allowing the detent ball to be released to carry out radialavoidance.

It is of disadvantage in the prior known tool system that the detentball which serves for the axial fixing must absorb the forces whicharise during use in accordance with the purpose of the combination tool.Upon frequent use of the combination tool this leads to a rapid wear ofthe detent ball. Also not satisfactorily is the lagging in centering ofthe tool within the adapter.

From DE 28 22 372 A 1 is also known a tool system which comprises a toolholding fixture and a combination tool. The combination tool describedcomprises a shaft with a hexagonal profile which has two functionalsections that coaxially extend. This combination tool is received in ahexagonal recess of an adapter which is adapted to the hexagonal profileof the tool shaft. In axial consideration the combination tool supportsitself with a conical transition section, between tool shaft andfunctional section, at an equally conical ring shoulder of the adapter.So as to protect the combination tool from falling out, the radialrecess of the adapter receives a detent ball which is radially movablein limited manner against the action of spring forces, which co-actswith the functional section arranged ring groove. During use of thecombination tool, the axial forces are absorbed by the ring shoulder ofthe adapter and not, as is the case in the device according to EP-O 685300 A 1, by the detent ball. However, also in EP-O 685 300 A 1 thecentering of the combination tool in the adapter is not satisfactory.

Another tool system which is comprised of a tool holding fixture and atool system which is comprised of a tool which is releasably receivedtherein is described in U.S. Pat. No. 5,013,194. The tool holdingfixture comprises a sleeve-like adapter furnished with hexagonalrecesses which is connectable with the drive shaft of a rotary tool.Into the hexagonal recess can be slid a tool having a shaft withhexagonal profile as well as a functional section coaxially extendingwith this. For axial fixing of the tool into the shaft of the toolholding fixture an annular groove is provided and in the wall of theadapter are arranged at same angular distances several detent ballswhich project in a locking position with a calotte into the recess ofthe adapter and reach into the annular groove of the tool shaft.Simultaneously the tool supports itself at the face-side directedtowards the rotary tool of the hexagonal recess directly at the adapter.EP 0 685 300 A 1 also consists of the detent ball that is held in thelocking position by a locking sleeve which is axially movable receivedon the adapter, which can be moved through axial shifting into aposition which allows the detent ball to move into a radial, avoidancereleasing position.

Also, in this prior known device, the centering of the tool in the toolholding fixture is not satisfactory. Furthermore, the tool holdingfixture does not allow the use of a combination tool.

In accordance with this the invention, is an improved tool system havinga tool holding fixture and a receivable tool therein, in which thedrawbacks of the prior known tool systems are avoided and in whichparticularly the centering of the tool is improved.

This aim is solved through a tool system with the features of claim 1.

In contrast with the prior art this tool system in accordance with theinvention consists of a shaft, which is received in the polygonal recessof the reception cylinder of the tool, is supported at a centering rangeand thereby, on the one hand, is centered and, on the other hand, duringuse of the tool arising axial forces are absorbed. The detent recess ofthe tool shaft contains detent elements that are uniformly distributedabout the circumference and co-act with the centering range of thepolygonal recess which in comparison with the state of the artsubstantially improves the centering of the tool in the tool holdingfixture. The radial forces arising in the detent element are low whenthe tool is used in accordance with its purpose, since they have toabsorb such axial forces which arise on retracting of the tool from itsoperative position

The centering range of the tool holding fixture may preferably beaccomplished with a conical support shoulder which is coaxially arrangedwith the drive shaft directing end of the polygonal recess of thereception cylinder, whereby the shaft of the tool at its end remote fromthe functional section has a centering cone which corresponds to theconical support shoulder. An appreciably improved centering of the toolsystem is obtained through co-acting of the support shoulder and thecentering cone.

In another embodiment of the invention, the locking sleeve is axiallyconfigured on the reception cylinder of the tool holding fixture andcomprises a movable sliding sleeve and a locking section which serves tohold the detent elements in their detent position, and one to thisconnected retention section, which retention section exhibits means forpositioning of the locking sleeve in the locked and unlocked position.This two part configuration of the sliding sleeve is particularly ofadvantage under considerations of production-technology.

In the case of utilization of ball-shaped detent elements it has beenshown as being useful when the locking section of the locking sleeve hasa support surface which is adapted to the contour of the detent ballsand can support the detent balls in the detent position insurface-contact manner. Thereby, due to appearance of axial forcesduring retraction of the tool from its position of use, low surface-areapressures are ensured between the detent balls and the mentioned supportsurface of the locking section

As means for arresting positioning of the locking sleeve its retentionsection can, usefully, be equipped with a detent element and thecylinder mantle of the reception cylinder can have at least one detentrecess into which, as a function of the prevailing position of thelocking sleeve, the detent element releasably extends.

Instead of only one detent recess naturally in the cylinder mantle ofthe reception cylinder which receives the locking sleeve can also beequipped with two detent recesses for selectively positioning of thelocking sleeve, which are axially separated at such a distance that inthe case of co-acting of the detent element with the one detent recess,the detent elements in their detent position are held, and in the caseof co-acting of the detent element with the other detent recess, thedetent elements for radial avoidance are released into their unlockedposition.

The locking section and the retention section of the locking sleeve canbasically be connected in any manner with one another. An especiallysimple and cost-efficient embodiment is a force-locking connection, likethrough a clip-connection. The locking section of the locking sleeve iscomprised of a material of high hardness, like steel, while theconfiguration of the locking section having been made of a somewhatelastic properties exhibiting synthetic-plastic has been shown to beuseful.

The tool holding fixture can be connected fixedly or releasably to thedrive shaft of a rotary tool. It has been found useful, however, tochoose a releasable connection, like by means of a coaxially from thereception cylinder further extending clamping plug and received in theclamping jaws arranged at the drive shaft of the rotary tool.

Within the frame work of the invention there can also be provided adepth abutment which can be releasably mounted on the tool holdingfixture which is adapted to be received coaxially in the rearwardsection on the reception cylinder of the tool holding fixture, andcomprises a forward section which is rotatably journalled at therearward section.

When using such a depth abutment it is, for one, given a precise deptharranging for the respective tool, and, on the other hand, it is alsoensured that on reaching the predetermined depth the forward section ispositioned atop the work piece and, in consideration of its rotatablyjournaling at the rearward section does not participate at its rotation,so that no scratches can arise at the work piece.

In such depth abutment it has also shown advantageous when the forwardsection is releasably connected to the rearward section, like through aclip connection. Through this selectively forward sections withdifferent extents in length can easily be coupled to the rearwardsection of the depth abutment and thereby in most simple mannerdifferent depths can be used.

The depth abutment per se, can by use of a lock means which extends intoa corresponding detent recess of the reception cylinder, be releasablyconnected with the reception cylinder such that a simple and rapidassembly and disassembly of the depth abutment is assured. The depthabutment can, however, be longitudinally adjustably configured, by meansof a threaded section between the forward and the rearward section, soas to allow an adaptation to the respectively required working depth.

Instead of a tool with a functional section extending coaxially at oneend from the tool shaft, there also a combination tool that can beprovided at which at both ends of the tool shaft are arranged co-axiallyto this further extending functional sections.

Such a combination tool has two longitudinal axes which each comprises ashaft section with a polygonal recess of the reception cylinder adaptedpolygonal profile and of a functional section, part-tools, the shaftsections of which are connected to one another.

For this purpose, in another embodiment, the ends of the shaft that faceeach other are furnished with connection sections, which have undercutsfor force-locking engagement of coupling means. As coupling means can beusefully provided a connection part axially with respect to one anotherfacing coupling recesses for shape-locking insertion into the undercutsat the ends of the shaft sections.

A further embodiment provides that the connection sections of thepart-tools are for axial force absorption at their face-side positionedtowards one another and are in contact with one another, and that aconnection piece is provided a coupling ring which has round bulges forengaging in the undercuts, made of a solid, however, in limited mannerelastic material, like plastic-synthetic material.

A further embodiment of the combination tool, in the interest of arotation-fast connection between the part-tools, provides that theundercuts of the connection sections are constructed to benon-radially-symmetric and co-act with a correspondingly shapedconnection part in shape-locking manner such that the shaft sections ofthe part-tools are rotation-fast connected to one another and with theedges of their polygonal profiles are with respect to one another in analigned manner fixed in position. The undercuts can have a cross-sectionin the shape of a circle-segment and the connection part is thenfurnished with corresponding circle-segment-shaped coupling recesses.

Within the frame work of the invention, the connection of the part-toolscan also be done in such a way that the ends of the shaft sections whichare directed towards one another are respectively furnished with acentral bore and in these bores is received a connection pin as well asthrough holding screws is fixed, which, in turn, are received intransversely to the central bores of the part-tools extending threadedholes.

A further important embodiment of the tool provides that the respectivefunctional section or at least one of the part-tools is releasablyconnected with the shaft or, respectively, with the shaft section of thepart-tool. For this the functional section is received in an axiallyshiftable manner in a bore of the shaft or, respectively, of the shaftsection, however, is fixable in a predetermined axial position by meansof a screwed-in arresting screw, secured radially into the wall of theshaft or, respectively, the shaft section transgressing threaded bore.

Another embodiment of the invention is where a step borer is thefunctional section and is provided with two different drillcross-sections. Such a step drill has been proven advantageous forconnection of two construction parts, for example, it requires athrough-bore in the one construction part and one with this through-borealigned pre-bore for turning-in of a connection screw in the otherconstruction part.

The tool configuration can, however, also be such that the shaft of thetool or, respectively, the shaft section of the part-tool has a centralpolygonal recess, preferably a 1/40 hexagonal recess, for reception of acorresponding functional bit, like a screw drill bit. Such a screw drillbit can be held, for example, by means of a holding magnet received inthe polygonal recess of the shaft, axial-fast, but releasably.

Finally, a further embodiment also provides that a part-tool of thecombination tool at its shaft-part end which is remote from the otherpart-tool, is provided with a sink section and an axially projectingdrill beyond this functional section. In such a tool configuration it isachieved in simple manner in succession to the drilling step to carryout a sinking of the bore hole, for example, for the receipt of a screwhead. In this case, the sink section is a 90°-sink.

Within the scope of the invention the sink section can be laid-out forbeveling of drill holes for subsequent provision of a threaded hole andthat the part-tool which is remote from the sink section is equippedwith a tap drill which is adapted to the drill cross-section of thedrill. With such tool configuration success is had with the forming ofthe bore hole for the subsequent cutting of threading and the bevelingof the bore hole in immediately successive steps, the forming of athreaded hole after re-tooling of the tool in the tool holding fixturesuch that the tap drill projects beyond the tool holding fixture.

In a further advantageous embodiment of the tool system, in accordancewith this invention, a torsion zone and/or bending zone is provided inthe reception cylinder of the tool holding fixture, between the detentreceiving elements provided radial recesses and the centering range ofthe polygonal recess.

So as to improve the operation of the tool system, in accordance withthe invention, the reception cylinder is secured at the tool holdingfixture via a safety coupling, preferably, a slip clutch.

The enclosed drawings that follow show the embodiments of a tool holdingfixture and a depth abutment as well as several tool configurations inaccordance with the invention are to be further explained. In schematicviews show:

FIG. 1 a sleeve-like tool holding fixture with an on this arrangedlocking sleeve in a longitudinal sectional view,

FIG. 2 a cross-section of the tool holding fixture along section lineII—II in FIG. 1,

FIG. 3 a cross-section through the tool holding fixture in accordancewith section line III—III in FIG. 1,

FIG. 4 also a cross-section through the tool holding fixture alongsection line IV—IV in FIG. 1,

FIG. 5 an enlarged portion of FIG. 1 details of the axially movableguided locking sleeve on the reception cylinder of the tool holdingfixture for selectively arresting or release of detent balls,

FIG. 6 a depth abutment which can be coupled to the tool holding fixturein part in side view and in part in a longitudinal sectional view,

FIG. 7 a drill tool which can be coupled to the tool holding fixture,

FIG. 8 a combination tool shown in part in cross-section, comprised ofto part-tools connected to one another,

FIG. 9 a half-sectioned of the rotation-fast connection of twopart-tools as combination tool,

FIG. 10 the rotation-fast connection of two part-tools in across-section in conformity with section line X—X in FIG. 9,

FIG. 11 in a view as in FIG. 8 another combination tool with atfront-face abutting part-tools,

FIGS. 12, 13 further combination tools in views as in FIG. 11,

FIG. 14 in a section-manner sectional view of a tool holding fixture thereception cylinder of which is furnished with a polygonal recess forreceiving a tool, with a torsion zone,

FIG. 15 in a view as in FIG. 14 a tool holding fixture, the receptioncylinder of which has a torsion/bending zone and

FIG. 16 again in a view as in FIG. 14 of a tool holding fixture, thereception cylinder of which is furnished with a polygonal recess forsecuring of a tool and is secured via a slip clutch.

FIG. 1 shows an embodiment of the tool holding fixture 10 and thesleeve-like adapter with a clamping plug 11 which can be received in aclamping jaws assembly, like of a hand drill (not shown), rotation-fastand thereby is capable of being coupled to its drive shaft and coaxiallyattached to the clamping plug 11 arranged reception cylinder 12. Fromthe side of the reception cylinder 12 which is remote from the clampingplug 11, extends into this a hexagonal recess 13 which to the clampingplug 11, which is pipe-like formed and exhibits smaller diameter thanthe reception cylinder 12, is terminating in a conical support shoulder14.

The mantle of the reception cylinder 12 is in distant manner from thesupport shoulder 14 transgressed by three radial recesses 15 which areevenly distributed about the circumference of the reception cylinder andinto which respectively one detent ball 16 is received. The radialrecesses 15 are becoming more slender from the outside to the inside insuch a way that the detent balls 16 in the radial recesses 15 are held,however, in their end positions project with ball calottes into thehexagonal recess.

On the reception cylinder 12 of the tool holding fixture 10 is anaxially movable guided locking sleeve 18 which, as is depicted in FIG.2, in a locking position arrests the detent balls 16 into theirhexagonal recess 13 projecting position, and in an unlocking positionreleases, for radial avoidance, as is depicted in FIG. 3. The lockingsleeve 18 is comprised of an annular locking section 19 and a therewithform locking, fixedly connected retention section 20. In some cases theretention section is made of an elastic plastic-synthetic injection-castpart. The locking section 19 can be configured as metallic,alternatively, however, it is also possible to make the locking section19 of plastic-synthetic so as to utilize the elastic behavior of thematerial of construction for a nearly fully tolerance-free toolcentering. Upon the introduction of the detent balls 16 into the radialrecesses 15, the retention section 20 is slid, from the side facing theclamping plug 11, onto the locking section 19 and extends over from thisradially projecting cylinder segments 22.

An annular groove 23 extends into these cylinder segments, into whichform-lockingly extends an adapted annular band 24, which projectsinteriorly radially from the retention section 20 and is snapped inafter the sliding of the retention section 20 in the direction to theclamping plug 11 projecting cylinder segments 22 of the locking section19.

In the area of the in the radial recesses 15 received detent balls 16 onthe inner side in the locking section 19 of the locking sleeve 18 arecut-in longitudinal grooves 26 which exhibit a cross-section with aradius which is equal to the radius of the detent balls 16 and, on theside which is remote from the retention section 20, terminate in suchsame bent formations, as is depicted in FIG. 5. In the locking positionshown in FIG. 1 of the locking sleeve 18 the detent balls 16 are intheir detent position by projecting into the hexagonal recess 13 of thereception cylinder 12 and are supporting themselves on the outer side atthe longitudinal grooves 26 in surface-area manner. Aligned with thelongitudinal grooves 26 there extend in the locking sleeve 18 from ashoulder 27 axially limited recesses 28, as free-spaces for the receiptof the detent balls 16 in their unlocking positions.

To the tool holding fixture 10 in selective manner can be coupled adepth abutment 30. The depth abutment is comprised of a side which isremote from the clamping plug 11, on the reception cylinder 12receivable rearward section 31, to which is connected via a ball bearing32 a forward section 33. The rearward section 31 of the depth abutment30 is formed by a plastic-synthetic ring with a central recess 34 whichis adapted to the outer diameter of the reception cylinder 12, intowhich projects a ring bulge 35 which projects at the end remote from theball bearing 32. An inner ring 36 of the ball bearing 32 is received bythe plastic-synthetic ring formed rearward section 31 which projectsradially into the central recess and thereby forms an axial limit to thereception cylinder 12 adapted central recess 34. By the forward section33 of the depth abutment 30 is also made of a plastic-syntheticinjection-cast past which extends about an outer ring of the ballbearing and under a certain spring pre-tension is received on this in areplaceable manner. Thereby succeeds the equipping of the depth abutment30 with forward sections of different lengths. There is also a threadedsection 31′ that is disposed between rearward section 31 and forwardsection 33. Threaded section 31′ allows depth abutment 30 to belongitudinally adjusted.

During use, in accordance with this invention, the rearward section 31of the depth abutment 30 is received on that end of the receptioncylinder 12 which is remote from the clamping plug 11, whereby thecentral recess 34 projecting edge bulge 35 engages into an exteriorlyannular groove 37 cut into the reception cylinder 12.

When in the polygonal recess 13 of the reception cylinder 12 a tool isreceived and by means of the detent balls 16 axial-fast is held, thefunctional section, for example, a drill, projects from the remote sideof the clamping plug 11 from the reception cylinder 12 and the on thisreceived depth abutment 30. When with such a drill a bore is made,whereby in consideration of the force-locking reception of the rearwardsection 31 of the depth abutment 30 on the reception cylinder 12, thedepth abutment also co-rotates, upon reaching of a certain drill depththe forward section 33 of the depth abutment 30 with its front facewhich is remote from the ball bearing 32 is supported on the work pieceand does not participate in any further rotation of the tool holdingfixture 10 and therewith the work piece, due to its via the ball bearing32 imparted rotatable connection with the rearward section 31. Thisavoids scratches on the work piece. In consideration of thereplace-ability of the forward section 33 of the depth abutment 30against forward section with other lengths, the depth abutment 30 can beutilized for limiting different bore depths.

There can be coupled with the tool holding fixture 10 a tool 40 as isdepicted in FIG. 7, in rotation-fast manner. The tool 40 has a shaft 41with a hexagonal profile which is adapted to the hexagonal recess 13extending into the reception cylinder 12. The shaft 41 is concluded at aface end a to the conical support shoulder 14 of the reception sleeve 12adapted centering cone 42 and from the other end of the tool shaft 41extends from drill 43. In the tool shaft 41 is arranged at a distancefrom the centering cone 32 which is equal to the axial distance betweenthe hexagonal recess 13 of the reception cylinder 12 limiting supportshoulder 14 and the detent balls 16 a surrounding annular groove 44 asdetent recess, which is adapted to the contour of the detent balls 16and into which in the locking position of the locking sleeve 18 thedetent balls 16 form-lockingly engage and thereby in the range of thelongitudinal grooves 26 in the locking section 19 of the locking sleeve18 support themselves. In this position the locking sleeve is arrestedby a detent element 46 which is arranged at spring, arm 47 extendingfrom the retention section 20 of the locking sleeve 18 between thecylinder segments of the locking section 19 and form-lockingly engagesinto a surrounding annular groove 48 of the reception cylinder 12.

When the locking sleeve 18 is actuated from this locking position into aunlocking position towards the side remote from the clamping plug 11,the detent element 46 engages into a corresponding distance from thefirst annular groove 48 into the reception sleeve 12, cut second annulargroove 49. In this position of the locking sleeve 18 longitudinalgrooves 26 are axially cut into the locking section 19 these arrangedrecesses 25 stand over the radial recesses 15 received detent balls 16in them such that the latter can evade in such a manner into therecesses 28 that no ball calottes project into the hexagonal recess 13of the reception cylinder 12.

In this unlocking position the shaft of a corresponding tool can beintroduced into the hexagonal recess and also be removed from this.

FIG. 8 is in contrast with this depicted combination tool 50 thatcomprises a two part-tool with face-ends connected to one another, withrespectively one shaft section 51, 52 with hexagonal recess 13 of thereception cylinder 12 adapted hexagonal profile, and one from therespective shaft section projecting functional section 53, 54. At theends of the shaft that face one another sections 51, 52 project fromthis mushroom-shaped coupling elements 55, 56 with undercuts. Betweenthe shaft sections 51, 52 is arranged a connection part 57 made oflimited elastic material, for example, a suitable plastic-synthetic,which in face-side ending coupling recesses receives the couplingsections 55, 56 of the shaft sections 51, 52, and extends behind theirundercuts. Respectively the projecting coupling plugs 55, 56 of theshaft sections and the coupling recesses of the connection part arefurnished with a flat portion 58 which provides a rotation-fastconnection to the shaft sections 51, 52 with one another. Furthermore,the connection part in congruency with the shaft sections 51, 52 arefurnished with a hexagonal profile and in the connection part extends ina surrounding manner an annular groove 59, as a detent recess, intowhich reach in accordance with the purpose of use of the combinationtool 50 the detent balls 16 of the tool holding fixture 10.

In the case of the functional section of the one part-tool, a drillwhich is rotation-fast is received in an axial bore 60 of the shaftsection 51. On the side directed to the drill is immediately formed tothe shaft section 51 a sink section 61. The other shaft section 52 isformed with a directly formed cross-slot screw tool.

Also FIG. 11 depicts a combination tool 64 that is comprised of twopart-tools with respectively one shaft section 65, 66 and from thisprojecting functional section 67, 68. At the functional sections remoteends, from the shaft sections project coupling sections 69, 70 withundercuts, but the coupling sections of the two shaft sections 65, 66are positioned in facing manner in contact with at one another, which isin contrast to the embodiment in accordance with FIG. 8. The two shaftsections are held together by means of an annular connection piece 72which surrounds the coupling plugs 69, 70 and extends behind theirundercuts.

Furthermore, in contrast to the embodiment in accordance with FIG. 8,respectively, distanced from the connection piece, the shaft sections65, 66 are furnished with surrounding grooves 73, 74 as, for use inaccordance with the purpose, with detent balls 16 of the tool holdingfixture 10 co-acting with the detent recesses.

By the functional section 67 of the one part-tool there is a step drillwhich is received in a longitudinal bore 75 of the shaft section 65 in alength-adjustable manner and is fixed by means of a small screw 76,which is received transversely to the longitudinal bore 75 extendingthreaded bore.

FIG. 12 depicts a functional tool 78 which there extends respectivelyfrom the end of the shaft sections 79, 80 that face one another intothis a central bore 81 in which is received a plug 82 which connects thetwo shaft sections 79, 80. Fixed on the plug 82 are the two shaftsections 79, 80 by means of respective small screws 83, 84 which arereceived in a threaded bore extending transversely to the longitudinalaxis of the shaft.

The one shaft section 80 of the embodiment, in accordance with FIG. 12,is equipped with an axial bore adjustable by means of a screw secureddrill 85 that enters a transversely extending threaded bore, and theshaft section end is formed as 120° sink section 86. The other shaftsection is equipped with a tap drill 87 as the functional section, theother end of the bore section is received in the longitudinal bore ofthe respective shaft section 79. The shaft section 79 has at the enddirected towards the tap drill 87 a shoulder 88 by means of which thetool 78 in the mounted condition can axially support itself on thesupport shoulder 14 of the tool holding fixture 10. At the same time,this shoulder 88 serves to provide as depth abutment so as to avoid thetap drill being supported at the tip during the production of threadedsack-holes. Furthermore, the shaft section 79 is provided with a torsionzone 89.

The combination tool 90 depicted in FIG. 13, describes a functional toolin the same manner as the above and in combination with FIG. 8. Combinedshaft sections 91, 92 is equipped with a drill 93 received in alongitudinal bore by means of a small screw secured drill 93, and thedrill directed end being equipped with a 90° sink section 94. The othershaft section 91 is equipped with a 1/40 hexagonal recess 95 andreceives a rotation-fast shaft of a screw drill bit. At the bottom ofthe hexagonal recess 94 is a holding magnet 96 that holds the screwdrill bit 97 sufficiently axial-fast.

FIG. 14 shows a tool holding fixture 100 that is different from the toolholding fixture 10 whereby the wall of the reception cylinder 12 is in alimited range, between the support shoulder 14 and the detent balls 16,and is of considerably reduced thickness and thereby forms a torsionzone 101. However, instead of a torsion zone 101, as shown in FIG. 15, atorsion and/or bending zone 102 can be provided in the receptioncylinder 12 between the conical annular shoulder 14 and the detentelements. This torsion and/or bending zone can either be comprised of awave-like hose part of the wall of the reception cylinder 12, or of anelastic material section of cylinder 12. The torsion and/or bending zone102 also allows, to a limited extent, the actuation of the tool throughan angle, inclined with respect to the axis of rotation of the driveshaft of a rotary tool.

So as to protect the tool system, in accordance with the invention, bylimiting the torque which can be imparted against overloading, and toprevent damage to the tools and work pieces, FIG. 16 depicts a toolholding fixture 120 that provides a reception cylinder 12 which containsa slip clutch 105 with the clamping plug-side portion 103. As opposed tothe foregoing described tool holding fixtures 10, 100, 110 serving as asingle unit providing element, together with the clamping plug 11 withdirected section 103 of the tool holding fixture.

For this purpose the portion 103 of the tool holding fixture at theremote end from clamping plug 11 has a cylindrical recess 106, with itsinner diameter adapted to the outer diameter of the reception cylinder12. In the recess 106 is arranged an annular groove 107 which is for thepurpose of receiving a friction ring 108. In front of annular groove 107is a friction ring 108 interiorly projecting into recess 106, andextends into a radial groove 109 extending at reception cylinder 12.Thus, there is provided not only a reliable friction-lock connectionbetween the clamping plug-side portion 103 of tool holding fixture 120and reception cylinder 12, but, additionally, reception cylinder 12 isaxially fixed at portion 103.

What is claimed is:
 1. A tool system that can be coupled to a driveshaft of a rotary tool, such as a hand drill or a screw drillcomprising: a) a tool holding fixture coupled to the drive shaft of therotary tool said tool holding fixture having a reception cylinder whichcontains a polygonal recess and wherein said reception cylinder containsa centering range; b) a tool disposed in said polygonal recess of saidreception cylinder, said tool being fixed to said reception cylinderrotation fast, wherein said tool has a polygonal shaft adapted to fitinto said polygonal recess, wherein said tool has at least onefunctional section, and at least one centering section having at leastone annular groove wherein when said tool is in operation, saidcentering section fits into, and contacts said centering range on saidtool holding fixture, c) a locking sleeve disposed around said toolholding fixture, and axially movable around said tool holding fixture;and d) at least one detent element, disposed within said tool holdingfixture, and for engaging said at least one detent recess of said toolshaft, wherein said locking sleeve can be moved along said tool holdingfixture to alternately move said at least one detent element into alocked position with said detent recess or an unlocked position removedfrom said detent recess so that said tool can be either locked into, orunlocked from said tool holding fixture.
 2. The tool system according toclaim 1, wherein said centering range is shaped frusto-conically andcoaxially arranged with said polygonal recess of said receptioncylinder, and wherein said shaft of said tool has a centering sectionwhich is shaped to mate with said frusto-conically shaped centeringrange.
 3. The tool system according to claim 1, wherein said lockingsleeve further comprises: a locking section which holds said at leastone detent element in their locked position; and a retention sectionwhich can position the locking sleeve in the locked and unlockedposition.
 4. The tool system as in claim 3, wherein said at least onedetent element is in the form of a detent ball, and wherein said lockingsection of said locking sleeve has a contour of detent balls adapted tosupport a recessed surface in said reception cylinder so that said atleast one detent element can support themselves in the detent positionin a surface-contact manner.
 5. The tool system according to claim 4,wherein said retention section of said locking sleeve has at least onedetent element and said reception cylinder has at least one receptiondevice into which said at least one detent element releasably extendsfor positioning said locking sleeve.
 6. The tool according to claim 5,wherein said reception cylinder has a cylinder mantle having a first anda second reception device for selectively positioning said lockingsleeve wherein said reception devices are axially separated at such adistance so that when said detent element is held in said firstreception device said locking sleeve is held in a locked position, andwhen said detent element is held in said second reception device saidlocking sleeve is held in an unlocked position.
 7. The tool systemaccording to claim 6, wherein said locking section and said retentionsection of said locking sleeve are connected to each other in aforce-locking manner, through a clip-connection.
 8. The tool system asin claim 4, wherein said locking section of said locking sleeve is madefrom steel.
 9. The tool system according to claim 7, wherein said toolholding fixture is releasably disposed, in said clamping plug by meansof said clamping jaws.
 10. The tool system according to claim 1, furthercomprising a depth abutment which can be releasably mounted on said toolholding fixture, said depth abutment having a rearward section on saidreception cylinder, and a forward section which is rotatably journalledat said rearward section.
 11. The tool system according to claim 10,wherein said forward section of said depth abutment is releasablyconnected, by a said at least one detent element or a clip connectionwith said rearward section.
 12. The tool system according to claim 10,wherein said depth abutment is longitudinally adjustably configured, bymeans of a threaded section disposed between said forward section andsaid rearward section.
 13. The tool system according to claim 1, whereinsaid tool is formed as a combination tool, wherein said combination toolshaft is disposed coaxially from said extending functional sections. 14.The tool as in claim 13, wherein said combination tool is comprised oftwo sections extending along a longitudinal axis of said tool, with saidtwo sections comprising a shaft section, shaped to fit into saidpolygonal recess of said reception cylinder and a functional sectioncoupled to said shaft section.
 15. The tool system according to claim14, wherein said shaft section have a connection sections havingundercuts.
 16. The tool system according to claim 15, further comprisinga connector for coupling two of said combination tools together at anend of said shaft sections with said connector connecting into saidconnection sections.
 17. The tool system according to claim 13, whereinsaid functional section is releasably connected with said shaft sectionof said combination tool.
 18. The tool system according to claim 17,wherein said shaft sections have a bore extending longitudinally thereinwherein said functional section is axially shiftable in said bore, andwherein said shaft section has a threaded bore extending substantiallyperpendicular to said longitudinal bore, and said system furthercomprises at least one arresting screw, for screwing into said threadedbore and for axially fixing said functional section in said longitudinalbore.
 19. The tool system according to claim 1, wherein said functionalsection comprises a step borer having at least two different drill crosssections.
 20. The tool system according to claim 19, wherein said shaftsection of said combination tool has a central polygonal recess, shapedas a ¼ hexagonal recess, for receiving a screw drill bit.
 21. The toolsystem as in claim 20, wherein said functional bit is held axially fastby a magnet but is releasably received in the polygonal recess of theshaft.
 22. The tool system as in claim 14, wherein said functionalsections on said shaft part end comprise a sink section and an axiallyprojecting drill.
 23. The tool system as in claim 22, wherein said sinksection comprises bevels for drill holes for containing a threaded hole,wherein the other part-tool has a tap drill which is adapted to thedrill a cross-section of the drill.
 24. The tool system as in claim 1,further comprising a safety coupling, for coupling said receptioncylinder to said tool holding fixture.
 25. The tool system as in claim24, wherein said safety coupling is a slip clutch.
 26. The tool systemaccording to claim 15, wherein said shaft section which is directedtowards one another, have a central bore wherein said shaft section inthe region of said central bore has at least one radially penetratingthreaded bore for receiving a holding screw.
 27. A tool system that canbe coupled to the drive shaft of a rotary tool, such as a hand drill ora screw drill comprising: a) a tool holding fixture coupled to the driveshaft of the rotary tool said tool holding fixture having a receptioncylinder which contains a polygonal recess and wherein said receptioncylinder contains a centering range; b) a combination tool disposed insaid polygonal recess, of said reception cylinder said tool being fixedto said reception cylinder rotation fast, wherein said tool has aplurality of shafts extending coaxially within said polygonal recess,wherein said plurality of shafts each have at least one detent recessand at least one centering section which fit into, and contact saidcentering range on said tool holding fixture when in operation, and atleast one functional section coupled to and extending coaxially withsaid shafts and wherein said plurality of shafts each have connectionsections having undercuts; c) a plastic coupling ring having roundbulges for engaging into said undercuts of said connection sections; d)a locking sleeve disposed around said tool holding fixture, and axiallymovable around said holding fixture; and f) at least one detent element,said at least one detent element disposed within said tool holdingfixture, and for engaging said at least one detent recess of at leastone of said plurality of shafts, wherein said locking sleeve can bemoved along said tool holding fixture to alternately move said at leastone detent element into a locking arrangement with said detent recess oran unlocking arrangement removed from said detent recess so that saidtool can be either locked in or unlocked from said tool holding fixture.28. The tool system according to claim 27, wherein said connectionsection is designed as non radially symmetric and co-act with acorrespondingly shaped connection part in a shape locking manner so thatsaid shaft sections of said part-tools are connected to each otherrotationally-fast, wherein said polygonal profiles of said shaftsections have edges that are fixed in position with respect to oneanother in an aligned manner.
 29. The tool system according to claim 28,wherein said undercuts have a cross-section in the shape of a circlesegment, and wherein said connection parts have a correspondingcircle-segment-shaped coupling recess.
 30. A tool system that can becoupled to the drive shaft of a rotary tool, such as a hand drill or ascrew drill comprising: a) a tool holding fixture coupled to the driveshaft of the rotary tool, said tool holding fixture having a receptioncylinder, which includes: i) a polygonal recess; ii) a centering range;iii) a torsion zone; and iv) a bending zone, wherein said torsion zoneand said bending zone being disposed between radial recesses providingthe reception of said at least one detent element and the centeringrange of said polygonal recess; b) a combination tool comprising aplurality of tools being disposed in and fixed rotation fast to saidpolygonal recess of said reception cylinder, wherein each of saidplurality of tools has a shaft and further includes: i) a centeringsection disposed within said shaft that fits into and contacts saidcentering range, wherein said centering section includes at least onedetent recess disposed on said shaft; ii) at least one functionalsection comprising at least one sink section disposed on said shaftwhich can bevel drill holes for containing a threaded hole, and whereinat least one tool of said plurality of tools includes said functionalsection having a tap drill which is adapted to a cross section of thedrill, a locking sleeve disposed around said tool holding fixture, andaxially movable around said holding fixture; and at least one detentelement disposed within said tool holding fixture, and for engaging saidat least one detent recess of said tool shaft, wherein said lockingsleeve can be moved along said tool holding fixture to alternately movesaid at least one detent element into a locking arrangement with saiddetent recess or an unlocking arrangement removed from said detentrecess so that said tool can be either locked in or unlocked from saidtool holding fixture.
 31. A tool system that can be coupled to the driveshaft of a rotary tool, such as a hand drill or a screw drillcomprising: a) a tool holding fixture coupled to the drive shaft of therotary tool, said tool holding fixture having a reception cylinder,which contains a polygonal recess and wherein said reception cylindercontains a centering range; b) a tool disposed in said polygonal recess,of said reception cylinder, said tool being fixed to said receptioncylinder rotation fast, wherein said tool has a shaft adapted to fitinto said polygonal recess, wherein said shaft has at least one detentrecess, at least one functional section, and at least one centeringsection which fits into and contacts said centering range on said toolholding fixture when in operation, c) a locking sleeve disposed aroundsaid tool holding fixture, and axially movable around said holdingfixture; d) at least one detent element disposed within said toolholding fixture, and for engaging said at least one detent recess ofsaid tool shaft, wherein said locking sleeve can be moved along saidtool holding fixture to alternately move said at least one detentelement into a locking arrangement with said detent recess or anunlocking arrangement removed from said detent recess so that said toolcan be either locked in or unlocked from said tool holding fixture; e) adepth abutment which can be releasably mounted on said tool holdingfixture, said depth abutment having a rearward section on said receptioncylinder, and a forward section which is rotatably journalled at saidrearward section; and f) a lock coupled to said depth abutment whereinsaid lock extends into, and is releasably connectable to a correspondingdetent recess of said reception cylinder.